Endless printing belts prepared by forming a base and a printing portion on a resin sheet of a certain type and impregnating the printing portion with ink for application to a rotary stamp have been publicly known (see Japanese Patent Application Publication Nos. 11-129595 and 11-129596, for example).
Similarly, endless printing belts prepared by forming a printing portion on a resin sheet and impregnating the printing portion with ink, and then subjecting side surfaces of the belt to melt-solidification for application to a rotary stamp have also been publicly known (see Japanese Patent Application Publication Nos. 2005-205798 and 2005-297461, for example).
The prior art according to Japanese Patent Application Publication Nos. 11-129595 and 11-129596 typically has a configuration to use a hot-melt sheet as a base material, to form a back-surface into a flat surface, and to render the entire surface ink-permeable. Moreover, this prior art also includes a configuration to use a non-porous sheet as the base material. Here, the back surface is formed into a flat surface as well.
Meanwhile, the prior art according to Japanese Patent Application Publication Nos. 2005-205798 and 2005-297461 has a configuration to apply a base fabric-attached porous stamp material using a base fabric such as a woven fabric or a nonwoven fabric, to form a back surface into a flat surface, and to render an entire surface ink-permeable. Here, side surfaces of the stamp material are subjected to melt-solidification.
These examples of the prior art have the following problems. Specifically, the one configured to render the back surface ink-permeable causes ink leakage from the back surface. In particular, when volatile-ink is used therein, these examples cause a loss of ink due to volatilization. Moreover, since the back surface is formed into a flat surface, a slipping action is caused when feeding the endless printing belt and a reliable feeding action is thereby complicated. As a consequence, it is difficult to position a printing portion accurately.